1. Field of the Invention
The present invention relates to a substrate mount type terminal used for the coupling between a vehicle-mounted electronic unit and a joint box in the wiring with in an automobile, for example.
2. Description of the Related Art
Conventionally, in order to couple an electronic unit and a joint box of an automobile, two kinds of techniques explained bellow have been put to practical use and actually used.
According to the first prior art, as shown in FIG. 12, a plurality of terminals are housed and disposed within a housing and integrated in a predetermined arrangement state thereby to form a connector 100. The connector 100 is attached to an electronic unit side and a connector at the end portions of wire harnesses drawn from a joint box side is coupled to the connector 100.
According to the second prior art, as shown in FIG. 13, a plurality of female terminals 115 are mounted on the substrate 110 of an electronic unit side in a predetermined arrangement state. A connector of wire harness side is coupled to the female terminals 115 thus arranged on the substrate 110.
Each of the female terminals 115 is arranged in a manner that a pair of pin-shaped lead portions 117 are provided so as to elect at the lower portions of a cylindrical terminal main body portion 116 into which a corresponding male terminal is inserted and coupled therewith. Each of the lead portions 117 is inserted into a through hole 110a formed at the substrate 110. Then, the lower end portion of each of the lead portions 117 protruded from the lower portion of the substrate, 110 is soldered on a predetermined wiring pattern formed on the substrate 110. Thus, each of the female terminals 115 is electrically coupled to the wiring pattern and also fixed to and mounted on the substrate 110.
According to the second prior art, since the predetermined arrangement and posture of the female terminals is held by directly mounting and fixing each of the female terminals 115 on and to the substrate 110, there is an advantage that the housing of the connector 100 employed in the first prior art can be eliminated.
However, in the case of the second prior art, in a provisional mounting state where the lead portions 117 of each of the female terminals 115 have been inserted into the through hole 110a of the substrate 110 but the lead portions 117 have not been soldered on the wiring pattern yet, each of the female terminals 115 is apt to move freely with respect to the substrate 110. Thus, there arises a problem that in case where other members contact to the female terminals 115 at the time of conveying the substrate 110, for example, the alignment of the respective female terminals 115 can not be held in a constant state.
Further, when the respective lead portions 117 are soldered on the wiring pattern, the female terminals 115 also freely move due to the surface tension etc. of the fused solder, so that the alignment of the respective female terminals 115 may also not be held in a constant state.
Furthermore, even in the state where the respective lead portions 117 have been soldered on the wiring pattern, a sufficient fixing force can not be obtained only from the soldering. For example, when the substrate 110 having the female terminals 115 mounted thereon is housed within the casing of the electronic unit, the female terminals 115 may contact to the casing etc., so that it is difficult to keep the alignment of the respective female terminals 115 in a constant state.
In this respect, in order to maintain constant the alignment state of the respective female terminals 115, it may be possible to employ such a method of using a housing for maintaining constant the alignment state of the respective female terminals 115 or a method of using a jig for adjusting the alignment. However, the former method is not suitable since the advantage of the second prior art that the connector housing used in the first prior art can be eliminated is spoiled. Further, the latter method is not suitable since a process of adjusting the alignment is required in addition to the process of mounting the female terminals on the substrate and so the fabricating process of the terminal becomes complicated.
Accordingly, an object of the invention is to provide a substrate mount type terminal which can maintain predetermined posture on a substrate as possible.
In order to attain the aforesaid object, the substrate mount type terminal according to a first aspect of the invention is arranged in a manner that in the substrate mount type terminal to be mounted on a substrate in which an attachment hole is formed, the substrate mount type terminal includes:
a terminal main body portion at which a coupling portion capable of being coupled to a coupled terminal in a fitting manner is formed at one end side thereof and an attachment base portion capable of being inserted into the attachment hole is formed at the other end side thereof;
a projection portion formed so as to protrude outward at an end portion of the terminal main body portion on the attachment base portion side; and
an engagement portion formed so as to protrude outward at a position of a side portion of the attachment base portion which is away from the projection portion to the coupling portion side by a distance enabling the substrate being sandwiched between the projection portion and the engagement portion.
In a second aspect of the invention, the terminal main body portion may be formed by a member of an almost cylindrical shape which can be inserted into the attachment hole of the substrate and one end side thereof is opened, and the coupling portion is formed as a female coupling portion in a manner that an extended piece extended from the opened end side of the terminal main body portion is turned down toward inside to thereby form a tongue piece for contacting to the coupled terminal side of male type.
Further, in a third aspect of the invention, the engagement portion maybe formed as an engagement piece which extends along insertion direction of the attachment base portion into the attachment hole portion and has a guide edge portion extending a to outside toward a direction opposite to the insertion direction.
Alternatively, in a fourth aspect of the invention, the engagement portion may be formed as an elastic engagement piece which is arranged in a manner that a side plate portion of the attachment base portion is cut and raised outward while remaining the coupling portion side as a coupling base portion and which elastically contacts to a peripheral edge portion of the attachment hole in a state that the terminal is mounted on the substrate.
In this case, in a fifth aspect of the invention, a portion of the side plate portion of the attachment base portion surrounding the elastic engagement piece is cut off at its periphery while remaining a part thereof thereby to form an elastic piece which can elastically deform freely within the cut area.
Further, in a sixth aspect of the invention, in place of arranging the engagement portion so as to protrude outward at the position of the side portion of the attachment base portion which is away from the projection portion to the coupling portion side by the distance enabling the substrate being sandwiched between the projection portion and the engagement portion, the engagement portion maybe arranged in a manner that the engagement portion is formed so as to protrude outward at a position of the side portion of the attachment base portion capable of contacting with pressure to an inner peripheral portion of the attachment hole in a state that the projection portion abuts against other surface of the substrate at a peripheral edge portion of the attachment hole.
Further, in a seventh aspect of the invention, the projection portion may be formed as a projection piece which is disposed along other surface side of the substrate and capable of being soldered to a printed wiring formed on the other surface side by means of reflow soldering.